Pinpoint Test G: The Lighting Control Module (LCM) Does Not Respond To The Diagnostic Tool

Test Step 

G1 CHECK THE LCM C2145a FOR DAMAGE 

• Key in OFF position.
• Disconnect: LCM C2145a.
• Inspect the LCM C2145a for damage.
• Is the LCM C2145a OK? 

Result / Action to Take 

Yes 

GO to G2.

No 

REPAIR the LCM C2145a. CARRY OUT the diagnostic tool data link test.

Test Step 

G2 CHECK CIRCUITS 914 (TN/OG) AND 915 (PK/LB) BETWEEN THE DLC C251 AND THE LCM C2145a FOR AN OPEN 

• Measure the resistance between the LCM C2145a pin 20, circuit 914 (TN/OG), harness side and the DLC C251 pin 2, circuit 914 (TN/OG), harness side.
  Fig 1: Checking Circuit 914 (TN/OG) Between DLC C251 And LCM C2145A For An Open

  Courtesy of FORD MOTOR CO.
• Measure the resistance between the LCM C2145a pin 28, circuit 915 (PK/LB), harness side and the DLC C251 pin 10, circuit 915 (PK/LB), harness side.
  Fig 2: Checking Circuit 915 (PK/LB) Between DLC C251 And LCM C2145A For An Open

  Courtesy of FORD MOTOR CO.
• Are the resistances less than 5 ohms? 

Result / Action to Take 

Yes 

GO to G3.

No 

REPAIR the circuit in question. CARRY OUT the diagnostic tool data link test.

Test Step 

G3 CHECK FOR CORRECT LCM OPERATION 

• Disconnect all the LCM connectors.
• Check for:
  • corrosion
  • pushed-out pins
• Connect all the LCM connectors and make sure they seat correctly.
• Operate the system and verify the concern is still present.
• Is the concern still present? 

Result / Action to Take 

Yes 

INSTALL a new LCM. REFER to MULTIFUNCTION ELECTRONIC CONTROL MODULES . CARRY OUT the diagnostic tool data link test.

No 

The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.